1. Field of the Invention
The system of the present invention relates to water clarification. More particularly, the system of the present invention relates to a method which incorporates a floatation vessel for separating, in particular, water and oil, in a manner such that the oil is floated to the surface of the water, and is allowed to channel out to be returned to storage, and the water is cycled through the vessel for clarification.
2. General Background
In the oil and gas industry, there is a continuing problem of the by-products of the oil and gas recovery process, wherein water produced in the process is contaminated with suspended oil and solids. In an oil and gas producing platform, water that is produced in the recovery of hydrocarbons from the well is usually contaminated with suspended oil and suspended solids, and can not be disposed of in the surrounding water, due to the stringent EPA requirements for disposing of products from the oil and gas recovery process.
The present state of the art utilizes a device which mixes and disburses gas in the form of fine bubbles in a body of liquid in a tank for attempting to remove contaminants from flowing water. This apparatus is covered by U.S. Pat. No. 4,255,262, issued to U.S. Filter Corporation, and employs a gas eduction system from the upper section of the respective tanks downward via a draft tube to the liquid body contained within the tank. Gas eduction occurs in a given portion of the liquid portion already contained when the vessel is recirculated back to the individual cells or compartments with a centrifugal pump. The apparatus also utilizes a mechanical skimmer assembly, electrically driven, which serves to remove the impurity laden froth from the surface of the liquid in the tank. Such skimmers are moderate to high maintenance components of a separation system particularly in corrosive environments in the oil producing and chemical plant industries.
U.S. Pat. No. 4,564,457, assigned to L'eau Claire Systems, Inc., teaches the use of a floatation cell system, wherein the fluid entrained with the gas is circulated into a plurality of baffled chambers, from the bottom of the tank, and as it rises upward, oil is collected onto the bubbles. There is situated a centrally located trough at the top of the vessel, so that as the water level of the vessel is raised, the froth in the top portion of the vessel collects into the trough, and the contaminants contained within the froth are then siphoned from the vessel.
Other patents issued in the art ar as follows:
______________________________________ Patent No: Issued to: ______________________________________ 2,274,658 R. B. Booth 2,782,929 W. W. Colket 3,468,421 B. S. Hazel, et al 1,648,558 J. R. Mesten, et al 1,612,557 E. C. Wiseburger 911,314 H. F. Maryville 2,825,422 O. B. Showenfeld 4,305,819 Kobozev, et al 2,942,733 H. A. Thompson 2,179,131 R. B. Miller 4,102,787 A. A. Gersten 4,147,629 A. A. Gersten 4,111,806 Wright, et al ______________________________________